Arrangements of reinforcing sleeves on the outer side of damping tubes in order to create a mechanical reinforcement for holding a receptive fork are known. Because of the limited wall thickness, the wall of a damping tube cannot in principle be adequately mechanically loaded in order to arrange the receptive fork directly on the outer side of the damper tube, so that a reinforcing sleeve is provided on the damper tube for mechanical reinforcement. Furthermore, in a manner known per se, the reinforcing sleeve has a bead, an annular bulge or the like in order to support the receptive fork against the reinforcing sleeve in the longitudinal axial direction.
The receptive fork is used for chassis attachment and, for example, is connected to an axle journal. Because of the increased forces that are introduced, the reinforcing sleeve is used to stiffen the lower end of the damping tube, the problem frequently occurring that, because of the gap that is formed between the inner side of the reinforcing sleeve and the outer side of the damper tube, gap corrosion occurs. As a rule, therefore, the peripheral edge delimiting the reinforcing sleeve axially in the longitudinal axial direction is welded to the outer side of the damper tube, for example with laser radiation. As a result, because of the action of heat on the damping tube as a result of the welding process, disadvantages result, in particular if the working piston is guided directly over the inner side of the damper tube. Here, it must be recorded that, even in welding processes with minimum introduction of heat, for example by using laser radiation, the action of heat on the damper tube is nevertheless so high that long-lasting operation of the vibration damper will possibly be disrupted, in particular if thermal distortion or an influence on the structure occurs. Even if only a surface impairment to the inner side of the damper tube occurs, long-term, long-lasting operation of the vibration damper can no longer be ensured.
The aim of laser welding is not only an integral connection of the reinforcing sleeve to the damper tube but also a hermetically tight connection of the peripheral edge, so that gap corrosion is avoided. Because of the disadvantages in the application of the welding process, a need exists for an alternative in order to avoid the gap corrosion, in particular without using a welding process.